Your doctor is right- MTX doesn't do much for spine inflammation of AS. I don't understand the mechanism, but MTX seems to only work on peripheral joints- fingers, toes, knees, elbows mainly.
TNF blockers, in my opinion, are safer than NSAID's. Taking NSAID's daily at high doses has a risk of cardiac event (heart attack, stroke) or gastrointestinal bleeding.
The main risk of TNF blockers is infection, the most serious is tuberculosis, but to be honest, the risk is quite low. I had my husband look at the data (he is an epidemiologist at a drug company) and the people who tend to get infections are elderly. If I lived around people that had tuberculosis, I would hesitate to take a TNF blocker, but most of us in the US are not at that great of risk. There is some risk of lymphoma, but it is very, very rare, there is a greater risk of having a heart attack from chronic NSAID use.
And taking TNF blocker early is the only treatment that has been shown to prevent damage to the spine over long term. NSAIDS help with pain and inflammation, but they don't prevent long term damage.
48 yo female, history of back pain since 1985, fatigue since 2009
-USpA diagnosis in August, 2015. Changed to PsA in 2016
-Erosions in finger joints
-Other: fibromyalgia dx in 2011 (wrong dx), endometriosis, severe pollen allergies
-Medications: Humira (since Oct, 2015). Weekly Humira start in Sept., 2016. Methotrexate (Dec. 2016). Aleve (as needed only), Lyrica, Tramadol, Baclofen, Vicoden, Tylenol, Xanax. Vitamin D, Vitamin B12, Folic Acid. Allergy Immunotherapy shots since 2009